Origin

Vigil comes from Latin vigilia ‘wakefulness’, from vigil ‘awake’. It was first used for the night before a religious festival, when people might stay wakeful all night in prayer. Related words include vigilant (Late Middle English); vigilance (late 16th century); and vigilante (mid 19th century) adopted from a Spanish word with the literal meaning ‘vigilant’. Surveillance (early 19th century) is from the same root and is literally watching over something, also found when someone invigilates (mid 16th century) an exam.